One thing to be very careful about in the future. If you did indeed put your meter in current mode and then measured between ground and the +5vdc power pin you were in fact short circuiting the +5vdc to ground. Something saved your ass, depending on how you are powering the board, either the USB thermofuse or the on-board +5vdc regulator going into overload protection mode.
Until you gain more knowledge and experience, be very careful measuring current. Measuring ohms (only with power off) and voltage (only with power on 
) are much less intrusive and dangerous, but current measurement can be very destructive if done incorrectly.
Lefty